cs5460 Cirrus Logic, Inc., cs5460 Datasheet - Page 9

• Manufacturer Part Number: cs5460
• Description: Single Phase Bi-directional Power/energy Ic
• Manufacturer: Cirrus Logic, Inc.

2. GENERAL DESCRIPTION
The CS5460 is a CMOS monolithic power mea-
surement device with an energy computation en-
gine. The CS5460 combines a programmable gain
amplifier, two
system calibration, and power calculation func-
tions to compute Energy, V
taneous Power.
The CS5460 is designed for power meter applica-
tions and is optimized to interface to shunts or cur-
rent transformers to measure current, and a
resistive divider or transformer to measure voltage.
To accommodate various input voltage levels due
to shunts, the current channel includes a program-
mable gain amplifier (PGA) which allows the user
to measure either 150mV
The CS5460 includes two high-rate digital filters
which output data at a (MCLK/K)/1024 output word
rate (OWR). A high-pass filter in both channels can
be enabled to remove the DC content from the input
signal before the energy calculations are made.
DS279PP5
N
modulators, two high rate filters,
R
2
To Service
RMS
Figure 3. Typical Connection Diagram (One-Phase 2-Wire)
R
1
RMS
or 30mV
L
470 nF
R
, I
S
* Refer to Input Current Protection
RMS
500
, and Instan-
RMS
RP
I
*
signals.
100 µF
500
CP
0.1 µF
I
*
To ease communication between the CS5460 and a
micro-controller, the converter includes a simple
three-wire serial interface which is SPI™ and Mi-
crowire™ compatible. The serial port also contains
a Schmitt Trigger input on its serial clock (SCLK)
to allow for slow rise time signals.
2.1 Theory of Operation
The CS5460 is designed to operate from a single
+5 V supply or dual ±2.5 V supplies, to provide a
30mV
channel and to provide a 150mV
voltage channel. With single supply, the CS5460 is
designed to accommodate common mode signals
of -0.25V to VA+.
Figure 3 illustrates the CS5460 connected to a ser-
vice to measure power in a single-phase 2-wire sys-
tem
configuration. Figure 4 illustrates the CS5460 con-
figured to measure power in a single-phase 3-wire
system.
CP
0.1 µF
V
10
15
16
12
11
*
9
RMS
while
VIN+
VIN-
IIN-
IIN+
VREFIN
VREFOUT
VA+
14
VA-
13
CS5460
or 150mV
10
operating
DGND
CPUCLK
PFMON
RESET
XOUT
EOUT
SCLK
4
EDIR
VD+
SDO
XIN
SDI
INT
CS
3
10 k
17
2
1
24
19
7
23
6
5
20
22
21
RMS
0.1 µF
2.5 MHz to
20 MHz
in
range for the current
Interface
Optional
Source
Serial
Clock
5 k
Data
a
RMS
single
range for the
CS5460
supply
9